Driving device employing maltese cross wheels



M. CHAMBON Sept. 29, 1931.

DRIVING DEVICE EMPLOYING MALTESE CROSS WHEELS Filed April 8. 1929 Patented Sept. '29, 1931 u r 'Immos mon, or.ramsjrmcnfassrenon To Ernmssmnnf'rs LQ-enmizon,

lor PARIS', 'FRANCE Elvira-:DEVICE EmrLoYrNG MALTESE cnosswnunts applicati@ mea April s, 1929, semi No. 353,505, am; 'm France Ain-Jil i9, 192s. 'l

. Improvements in driving devicesl employing Maltese cross wheels.

In driving devicesY in which Maltese cross wheels are employed, the angularl accelerations attain great values4 whichmake it nec- 'essary to limit the .speed of rotation. In`

particular, in the casein which the actuated parts have a certain inertia, for instance in machinev tools', the driving. gear is rapidly worn out, and the rollers' become jammed in the slots. l A All such drawbacks are obviated by the present invention, by giving to the rollers which enter the slots of the cross Wheel and thus drive the latter, no longer a unif/orm circular motion as before, but a variable m0- tion, such that thev maximum accelerations of the cross wheel are reduced. By the use ofadequate means, the shaft driving the rollers lcan be given a circular motion such a that the motion of the Maltese cross wheel I will vary according to a sinusoid.

' This result may even bev more simply obtained, by varying the distance between the rollers and their axis of rotation accordingto a periodic law whose periodis determined by thel number of slots in thel said cross wheel. Ina preferred uevice, I place par' allel to the roller-carrying disk, a station- 80 ary cam upon which are caused to roll suitable .auxiliary rollers eecting the radial displacement of the said main rollers, which latter are mounted for instanceV on a cross piece movable in a ide formed in the *drivlng disk. The said cam is preferably so 'arranged that when the Maltese cross wheel rotates,` its motion comes near a sinusoid.

The said cam may however be given any other form, so as to provide a motion particularly adapted to the work to be performed. Obviously, without departing from the spirit'of the invention, in the motion thus obtained, the accelerations of the Maltese cross wheel mayexceed those 'which would be obtained Without the cam.

f The following description relates to an embodiment of thev invention;

. In the accompanying'drawings vwhich are given by way of example: 5 Figure 1 is an elevational View of the ap- The device herein represented-,comprises so a frame-9 onwhich are mounted the .driving shaft-6 and the actuated shaft 14. To the shaft 6 is keyed. a disk 5 which drives the two rollers 1 by kmeans of a; device to be' further described. The said 'rollers 1', orv main rollers, assure, inthe usual manner, the movement of the Maltese cross Wheel `.10 by successively entering the four slots of the latter. The -rolrs v1 are mounted on the'ends of a cross piece 4 which is slid- .70 able en lthe rear side'of the said disk 5. For this purpose, the crosspiece 4 carries at its centre a. groove 12 into .which is inserted theend fof the shaft 6.- The rollers 1 are mountedrespectively upon the axles 11 serv- 'ing as cross braces between the rear cross piece 4 and the cross piece 3 which is parallel to the same and is disposed on the front side of the disk 5. f

The cross piece 4 is 'slidable between guides 2 secured to the disk 5 in such manner as to be drawn forward with thesame. At the rear of the disk 5, the cam 8 having a suitable outline is secured tothe frame 9 by pins such as 13. The axles 11 carry rollers 7 adaptedto roll upon the said cam 8. It is observedin Figure 1 that during the -rotation of the disk 5,.the rollers 7 will roll upon the cam 8, thus moving the cross piece 4 in its guides, in such malnner that the main rollers 1 are actuatedA atthe same time by Ia radial displacement which is superposed on their'rotation about the driving shaft 6. l

The form of thegcam 8 in the present exv ample is Isuch that ,thel movement of the Maltese cross wheel, when 'it rotates, comes near a sinusoid. The distance between the rollers 1 and their axisof rotation 6 becomes less fatt'he time at which, inthe usual rMal- 100' TNT oFFlCE as r iml

tese cross wheel, the acceleration is at the maximumjvalue, so that this acceleration will'be less, with this form of the cam 8. This apparatus can be employed to advantage to obtain a predetermined acceleration, and even, if the speed permits, with a law of the movement of the rollers such that the maximum acceleration exceeds the value which it would attain in the usual Maltese cross Wheel of corresponding construction.

Having now particularly described my invention and in what manner the same is to be performed, I claim asvmy invention:

1. Power transmitting device comprising a drive shaft, a driven shaft, a Geneva gear mounted on said driven shaft, a plate mounted on the drive shaft, a sliding member on said plate, a cam parallel with said plate, a roller mounted on said member and engaging with the cam, another roller mounted on said member, this latter roller engaging with the Geneva gear.

2. Power transmitting device comprising a drive shaft, a driven shaft, a Geneva gear mounted on said driven shaft, a`\ plate mounted upon said drive shaft, a sliding member upon said plate, a roller mounted upon said sliding member and engaging said Geneva gear, and cam means for modifying the path of movement of said roller so as to diminish the distance between said roller and said drive shaft when the roller is engaged-with said Geneva gear.

3. Power transmitting apparatus according to claim 11 in which the cam is of such formation that the movement of the Geneva gear is. substantially sinusoidal.

In testimony whereof I have signed this specification. 4

MARIUS CHAMBON. 

